[Forgive me if there's an existing topic on katsu; I couldn't find anything but this brief discussion of something that seems to have more content than is currently available.

So, two days ago, Matto gave me this gift:

I think... you think too much!
As I replied, I think he's right! Of course, he also got me thinking about gestures that help me not think too much. :wink:

I've learned enough by this point to realize that, sometimes, the thing I need most is for someone to shout, "Sit down and shut up!" (Usually, it's me both needing and shouting!) I don't know too much about it, but katsu seems to be the right name for this act.

Here's what Wikipedia has to say about katsu:

Katsu is a type of shout that is used in Chán and Zen Buddhism to give expression to one's own enlightened state (Japanese: satori) and/or to induce another person to move beyond rationality and logic and, potentially, achieve an initial enlightenment experience. ... The word in Chinese means literally "to yell" or "to shout", and in Japanese has also developed the meaning of "to browbeat", "to scold", and "hoarse". However, in the context of Chan and Zen practice, the word is not generally used in its literal meaning(s), but rather—much as with the martial arts shout of kiai—as fundamentally a means of focusing energy. ... The katsu shout, insofar as it represents a kind of verbal harshness and even violence, can be considered a part of the Mah?y?na Buddhist doctrine of "skill-in-means" (Sanskrit: up?ya-kau?alya), which essentially teaches that even an action or practice which seems to violate Buddhist moral guidelines—in this case, the Noble Eightfold Path's injunction against "abusive speech"—is permissible, and even desirable, so long as it is done with the aim of ultimately putting an end to suffering and introducing others to the dharma, or teachings of Buddhism.
I've been snooping through this pdf of The Zen Teaching of Rinzai, where one can find lots of Linji/Rinzai katsu moments. My favorite:

Linji asked a monk: "Sometimes a Katsu is like the precious sword of the Vajra king (Diamond King); sometimes a Katsu is like a golden-maned lion crouching on the ground; sometimes a Katsu is like a probing pole (for fishing) to which a grass bushel is fastened to cast shade; and sometimes a Katsu is not used as a Katsu. How do you understand that?"

The monk hesitated and the master gave a Katsu.
Compelling stuff, I think, that rubs against the "nice Buddhism" grain -- and for the record, I'm happy to have anyone katsu me here on Treeleaf at any time!

Seriously, I'd be interested to know more about how everyone here -- including Jundo and Taigu, of course -- approaches this... technique? tool? approach?